The field of the invention is conventional mining and milling and solution mining and the invention relates more particularly to the production of sodium carbonate or sodium bicarbonate from crude ores such as trona, nancolite, naturally occurring brines, or complex carbonate minerals. In the past, the Solvay process was commonly used for the production of soda ash, but the Solvay plant facilities in the United States and in other environmentally sensitive areas around the world have been shut down and abandoned since substantial amounts of calcium chloride were produced and there was no practical manner of recycling a disposal of this by-product. The Solvay process reacts the sodium radical in sodium chloride with the carbon dioxide present in limestone using ammonia as an interminable reactant.
Most domestically produced soda ash is produced from buried naturally occurring deposits of trona (sodium sesquicarbonate) in the Green River Basin in Wyoming. The ores are mined through deep shafts by conventional room and pillar or long wall mining methods. Soda ash is recovered by one of two common processes referred to by the industry as the mono hydrate process and the trona process. Both processes have the following disadvantageous: numerous operating steps; lack of efficiency, high manpower requirements; and high capital and operating costs.